1. Technical Field
The present invention relates to a recording apparatus.
2. Related Art
An ink jet printer forms dots on a matter for printing by ejecting ink droplets (liquid droplets) from nozzles according to recording data which denotes a presence or absence of a dot in each pixel, by relatively moving a plurality of nozzles which are aligned in a predetermined nozzle aligning direction and the matter for printing (matter for recording) in a relative movement direction which intersects the nozzle aligning direction. As the ink jet printer, there is a serial printer, a line printer, or the like.
In the serial printer, for example, ink droplets are ejected from a nozzle while causing a recording head to scan a matter for printing in the main scanning direction, the matter for printing is transported toward a transport direction which intersects the main scanning direction between main scanning operations, and an image using dots is printed on the matter for printing. In the serial printer, there is a printer which performs overlapping printing in which dots of a raster facing the main scanning direction are formed using a plurality of scanning operations. In the overlapping printing, partial overlapping printing in which a single region in which dots of a raster are formed in one main scanning operation, and an overlapping region in which dots of a raster are formed using a plurality of times of main scanning operation are printed is included.
In the line printer, for example, an image using dots is printed on a matter for printing by transporting the matter for printing without moving nozzles which are arranged approximately over the entire region in the width direction which intersects a transport direction of the matter for printing. Since nozzles are arranged approximately over the entire region in the width direction of the matter for printing, there is a line printer in which a plurality of recording heads with nozzle columns are used, and nozzles are overlapped with each other at a junction of neighboring two recording heads. When nozzles are partially overlapped, a single region in which dots of a raster is formed using one nozzle, and an overlapping region in which dots of a raster is formed using a plurality of nozzles are generated.
When ink droplets are not ejected from a nozzle due to clogging, or the like, or ejected ink droplets do not draw an exact track, a region of “dot omission” which is formed when a pixel in which a dot is not formed connected in a relative movement direction is formed, and a stripe such as a white stripe occurs in a printed image. In JP-A-2006-168104, an ink jet printer which includes a discharge-defective nozzle complementing unit, and a discharge-defective nozzle mitigation unit is disclosed. In the ink jet printer, a carriage on which a recording head including a plurality of nozzles is mounted performs scanning along a guide rail, a matter for recording is appropriately transported in a direction which is orthogonal to the guide rail, and an image is recorded on the matter for recording using multipass recording. When performing the multipass recording, recording is performed without transporting the matter for recording, exceptionally, with respect to a tip end portion and a rear end portion of the matter for recording. Here, in a normal printing in which recording is performed in a state in which transporting is performed, recording is performed using the discharge-defective nozzle complementing unit in which a control is performed so that data to be recorded using a discharge-defective nozzle is recorded using another nozzle which records data in another pass, and is on the same line. When performing an exceptional recording in which recording is performed in a state of no transporting, recording is performed using the discharge-defective nozzle mitigation unit in which data to be recorded using a discharge-defective nozzle is controlled so as to be recorded using a neighboring nozzle of the discharge-defective nozzle.
That is, in the technology which is disclosed in JP-A-2006-168104, when performing normal recording in which a matter for recording is transported, a complementing dot which complements a dot to be formed using a discharge-defective nozzle is usually formed in the same raster using a substitute nozzle in another pass.
In a serial printer which performs overlapping printing, when a matter for recording is transported, it is possible to form a complementing dot using a substitute nozzle in another pass with respect to a raster in which a dot is to be formed using a defective nozzle. However, there is a case in which a stripe (banding) which goes along the relative movement direction remains due to an error which occurs when the matter for recording is transported. Such a problem also exists in the technology which is disclosed in JP-A-2006-168104 in which a complementing dot is usually formed on the same raster, using a substitute nozzle in another pass at a normal time in which a matter for recording is transported. In particular, in a case in which a printer performs partial overlapping printing, when a nozzle which forms a dot at an end portion of an overlapping region which occurs in a printed image is a defective nozzle, the above described stripe is easily viewed.
In addition, in the line printer, it is possible to form a complementing dot in a raster in which a dot is to be formed using a defective nozzle, using a substitute nozzle in another recording head. However, there is a case in which a stripe which goes along the relative movement direction remains due to an error of a positional relationship between neighboring recording heads, or the like. In particular, when a nozzle which forms a dot at an end portion of an overlapping region which occurs in a printed image is a defective nozzle, the above described stripe is easily viewed.
In addition, the above described problem also exists in various recording apparatuses.